Japanese computer games publisher Sega has joined the rapidly growing club of video game companies whose computer systems have been hacked by cyber criminals.

The news capped a week in which the Lulz Security group of hackers launched a cyber crime spree against other video game companies and other multi-national bodies.

In an unexpected twist, Lulz responded to the news of the attack on Sega by offering to track down and punish the hackers who attacked the Japanese company.

Sega, known for its Sonic the Hedgehog games series, has written to customers to tell them that hackers got into the database for Sega Pass, its online gaming network.

"Over the last 24 hours we have identified that unauthorised entry was gained to our Sega Pass database," the company said.

"We immediately took the appropriate action to protect our consumers' data and isolate the location of the breach. We have launched an investigation into the extent of the breach of our public systems."

Customer email addresses and birthdates, which can be read in plain text were taken, as were passwords, which could not be read in plain text because they had been scrambled or encrypted using security software before being stored in the database.

Sega shut down the Pass network on Thursday, the day it learned of the breach, telling customers in a note on its website that it was "undergoing improvements."

It was not immediately clear when it would go back online.

Sega was one of the biggest video game consoles makers in the 1990s, but pulled out of the market in 2001 in response to disappointing sales of its Dreamcast system, which had debuted in 1998 to widespread industry praise.

Dreamcast lost ground to newer products developed by Sony and Nintendo.

Sega now focuses on developing video games for systems made by other companies.

Lulz gets involved

While the FBI is likely to be called in to investigate the attack on Sega, as the bureau typically is in such cases, its agents may find themselves competing for clues with members of Lulz Security hacking group.

In its offer to assist Sega, the Tweet from Lulz hinted that its leaders might count themselves among a small but highly loyal group of gamers who still play on the aging Dreamcast console.

"Sega - contact us," Lulz said in its Tweet to the video game developer.

"We want to help you destroy the hackers that attacked you. We love the Dreamcast, these people are going down."

Lulz offered to see that the cyber criminals are punished for attacking Sega shortly after ending its own crime spree that included attacks on several other video game companies.

The Lulz hackers, who publicise their attacks on their own website and via Twitter, said on Friday that they had stolen customer records of some 200,000 users of the online video game Brink.

Officials at Xenia Media, the developer of Brink, could not be reached for comment.

Lulz last week also attacked several other industry players, saying it was working on behalf of disgruntled players who had ordered the attacks via telephone hotlines that Lulz set up in the United States and Europe to solicit such requests.

Lulz had hacked into Nintendo in an attack that it disclosed on June 3, but the incident has not appeared to have serious consequences for the company.

The hacking group published a data file over the internet that it said contained details on the way Nintendo set up one of its web servers.

Such data could be valuable to other hackers planning future attacks on Nintendo because the data potentially could leave clues as to possible security weaknesses in the game maker's network.

Lulz also brought down the website of the US Central Intelligence Agency last week.

Australian Government departments, universities and schools also appeared to have been caught up in the actions of the notorious hacker group.

Sony dramas

The drama surrounding the recent round of video game breaches paled compared to what PlayStation maker Sony Corp experienced following two high-profile attacks that surfaced in April.

Those breaches led to the theft of account data for more than 100 million customers, making it the largest ever hacking of data outside the financial services industry.

They also exposed what turned out to be a large number of security holes in sites throughout the global Sony media empire.

That led to a rash of attacks on Sony systems that undermined confidence in the company and made it the source of frequent jokes by security experts.

Its security staff scrambled to repair vulnerabilities in its network as independent experts identified new problems via remote scans and disclosed them to Sony and the public.